Is there a problem of burning engine oil in cbr 1000 after 08?

There are many reasons for oil leakage, including: oil pipe, oil drain, oil pan gasket, valve cover gasket, oil pump gasket, fuel pump gasket, timing chain cover seal and camshaft seal. None of the above possible leakage factors can be ignored, because even a small leakage will lead to a large amount of oil consumption. For example, leaking a drop every 6 seconds means consuming 0.56 liter of engine oil every 100 kilometers. The best leak detection method is to put a light cloth on the bottom of the engine and check it after starting the engine. The location of leakage can be judged by the location of oil droplets on the cloth.

2. Failure of front and rear oil seals

Damage to the front and rear main bearing oil seals will definitely lead to oil leakage. This situation can only be found when the engine is running with load. The main bearing oil seal must be replaced after wear, because it will lead to high leakage like oil leakage.

3. Wear or failure of main bearing

Worn or faulty main bearings will spray too much oil and be thrown to the cylinder wall. As the bearing wear increases, more oil will be thrown out. For example, the bearing clearance of 0.04 mm can provide normal lubrication and cooling functions. If the bearing clearance can be maintained, the amount of oil thrown out is normal and will not damage the bearing. When the clearance is increased to 0.08 mm, the amount of oil thrown out will be 5 times of the normal amount. If the clearance is increased to 0. 16 mm, the amount of oil thrown out will be 25 times of the normal amount. If the main bearing throws too much oil, more oil will splash on the cylinder, which makes the piston and piston ring unable to effectively control the oil quantity. This can lead to burning oil or carbon deposition on pistons and piston rings. Usually, when the main bearing loses too much oil, the connecting rod bearing will be short of oil, which leads to insufficient oil splashing on the cylinder wall at some low speeds, resulting in the wear of the piston ring and piston, and the oil quantity cannot be controlled when the engine runs at high speed. Therefore, the result of main bearing wear is high fuel consumption.

4. The connecting rod bearing is worn or damaged

The influence of connecting rod bearing clearance on oil is similar to that of main bearing. In addition, the oil is thrown to the cylinder wall more directly. The wear or damage of connecting rod bearings leads to too much oil left on the cylinder wall, which leads to the piston and piston ring designed to control the normal oil quantity can not effectively control too much oil, so that the excess oil enters the combustion chamber for combustion, that is, the oil consumption is high.

5. The camshaft bearing is worn or damaged.

Camshaft bearings are usually pressure lubricated. If the clearance is too large, too much oil will leak. The leaked oil will wet the valve guide and valve stem, resulting in increased oil consumption.

6. Crankshaft journal wear

The influence of crankshaft journal wear on engine oil is the same as that of bearing wear. When the wear amount is circular, the gap between them and the circular bearing will be uneven. The clearance between the noncircular crankshaft journal and the bearing changes during the rotating motion, which will throw out more oil. Out-of-round bearings need to be reground and matched with smaller bearings.

7. The cylinder liner is ground to be conical or not round.

For the cylinder liner that is slightly tapered and out of roundness (cylindricity and concentricity decrease), the oil consumption can be controlled by the piston and piston ring. However, with the increase of cylinder liner taper and roundness, it becomes more and more difficult to control fuel consumption. This is the result of a combination of factors. With the increase of the clearance between the piston and the cylinder liner, the piston will swing during operation; This instantaneous tilt will cause too much oil to stay on one side of the piston, and the same will happen to the piston ring. In this way, as the piston keeps swinging back and forth, some oil will escape into the combustion chamber. Every time the crankshaft rotates, the piston completes two strokes, an upstroke and a downstroke. When the engine is running at 3000 rpm (about 60 mph), the piston ring running in the deformed cylinder liner will undergo 6000 changes in size and shape every minute. In this way, under the condition of high-speed operation, the piston ring may not be able to adjust its fit clearance with the cylinder liner in time (especially when it runs to the worn part of the cylinder liner, resulting in excessive fit clearance). So as long as the above situation occurs, the oil consumption will be too high.

8. Cylinder liner deformation

Different from the cylinder liner roundness caused by wear mentioned in 7, there are other reasons, such as uneven heating or uneven tightness of cylinder head bolts, which may lead to cylinder liner deformation, resulting in the piston ring not being able to form correct mating contact with the cylinder liner surface, and the oil scraping function is reduced; As a result, too much engine oil remains locally and eventually escapes into the combustion chamber for combustion, resulting in an increase in engine oil consumption.

9. The "PCV" crankcase forced ventilation valve or pipe is blocked.

The main function of PVC (Forced Ventilation of Crankcase) is to recover the mixture entering the crankcase from the engine combustion chamber and reduce the content of unburned hydrocarbons in it. The mixed gas is a mixture of air, fuel and combustion waste gas. During the power stroke, due to high pressure, it enters the crankcase through the gap between the piston/piston ring and the cylinder liner. PVC system usually has a pipe leading to carburetor or intake manifold through crankcase. The mixed blowby gas is sucked out of the crankcase by the vacuum generated when the engine intake manifold sucks air, and then enters the combustion chamber for recycling. The PVC valve may be blocked by sludge, paint film or other impurities in the mixed blowby gas. This will lead to deterioration of oil, excessive deposits, piston ring (oil ring) blockage, increased oil consumption and premature wear of piston ring; The increase of crankcase pressure leads to the failure of crankshaft sealing ring and oil leakage, which makes the engine working condition worse.

10. Honing abrasive wear

If the cylinder liner is honed or polished, it must be cleaned in strict accordance with the requirements to prevent residual metal chips or abrasives from damaging the piston ring groove surface. The cleaning method is as follows: after honing, the cylinder liner must be thoroughly cleaned with a brush dipped in soapy water, and then immediately oiled; Or clean the cylinder wall with 10# lubricating oil and wipe it carefully. Repeat the above process until all foreign objects are removed. No matter which method is adopted, the final inspection is needed: wipe the surface of the cylinder liner with a white cloth. If the white cloth is still clean after wiping, it means that the cylinder liner has been cleaned.

Note: Do not clean the honing cylinder wall with gasoline or kerosene. Because they can't remove the abrasive attached to the cylinder wall, and they will bring the abrasive into the honing micropores. Therefore, the cylinder liner that is not cleaned properly may lead to premature wear, piston ring failure, and eventually lead to an increase in oil consumption.

1 1. Wear of piston ring groove

Whether the end face of piston ring groove is flat or not and whether the clearance between piston ring and piston ring groove is correct are important factors for piston ring to play a good sealing role. Generally, the backlash of piston ring groove of automobile engine cannot exceed 0.002 "-0.004". When the piston moves up and down, the piston ring must be correctly embedded in the piston ring groove. If the piston ring groove is deformed, the piston ring will not work normally and the oil will flow into the combustion chamber. Worn piston ring grooves will increase the side clearance, which will lead to excessive oil escaping into the combustion chamber. On the other hand, excessive backlash will cause the piston ring to hit the piston ring groove, which will lead to further wear of the piston ring groove. If the situation is not improved, it will even lead to the fracture of the piston ring group.

12. The piston ring group is damaged or broken.

The damage or fragmentation of the piston ring group will cause the piston ring not to be properly embedded in the piston ring groove, which will lead to excessive oil flowing into the combustion chamber. In addition, it will lead to complete damage of cylinder liner, piston and piston ring. So pay close attention. Once this sign appears, it must be replaced immediately.

13. Worn valve stem or guide tube

If the valve stem and the guide tube are worn, the vacuum suction generated during intake will suck the oil and oil gas between the valve stem and the guide tube into the intake manifold, and finally enter the combustion chamber for combustion. If this situation is not improved, then when the engine is replaced with a new piston ring, the fuel consumption will also increase due to the increase of intake vacuum suction; When the engine is overhauled, the clearance will be further enlarged and the oil leakage loss will be more obvious after removing the deposits such as sludge originally attached to the surface of the valve stem and the guide pipe. For the engine with overhead valve, whether it is exhaust valve or intake valve, oil loss may occur. The problem of high fuel consumption caused by excessive valve guide clearance can be improved by constantly trimming the valve stem. Sometimes a new valve needs to be trimmed like this. Advanced adhesive valve seal can effectively prevent oil leakage and oil leakage.

14. Bending deformation of connecting rod

Bending deformation of the connecting rod will make the piston move linearly along the cylinder liner, which will affect the normal sealing function of the piston ring and increase the oil consumption. In addition, the bending deformation of the connecting rod will also lead to the change of the fit clearance between the connecting rod bearing and the piston pin, which will lead to the premature wear of the connecting rod bearing and more oil being thrown on the cylinder wall.

15. The piston pin is worn or improperly positioned.

If the piston pin is worn or improperly assembled, the oil flowing to the piston pin under pressure will be thrown to the cylinder wall, and the piston ring cannot scrape off the excess oil. This not only leads to the direct excessive loss of engine oil, but also the formed carbon deposit will block the oil circuit and cause the piston ring to be stuck.

16. Piston pin assembly is too tight.

If the two ends of the piston pin are assembled too tightly, the piston will not expand and contract normally under the repeated cold and hot working environment of the engine, which will lead to the deformation of the piston and scratch the cylinder wall, which will inevitably lead to gas leakage and excessive oil loss.

17. Oil circuit is blocked

When the engine runs for a long time under bad working conditions, the carbon deposit and foreign matter produced are easy to block the oil passages in the piston and piston ring. At this time, the oil can not return to the crankcase in a normal way, but stays in some parts such as the valve guide, resulting in an increase in oil consumption. If the connecting rod or other parts of the oil circuit is blocked, it will lead to poor lubrication of the engine, increased wear and fuel consumption. In order to avoid the above situation, the preventive measures mentioned in item 28 should be taken. Of course, there is no need to reserve a gap for this.

18. The torque of the main bearing cap bolt or connecting rod bolt is unbalanced.

If the torque of the main bearing cap bolt or connecting rod bolt is unbalanced, it will lead to the out-of-round deformation of the bearing, reduce the service life of the bearing, and cause excessive oil to be thrown out of the bearing, thus affecting the oil consumption mentioned in items 3 and 4. When installing the bearing cover bolts, the torque wrench must be used to tighten them strictly according to the manufacturer's requirements. If the torque of the connecting rod bolt is unbalanced, the connecting rod will be deformed, and the consequences are described in item 14.

19. Unbalanced torque of cylinder head bolts. The stress caused by the unbalanced torque of the cylinder head bolts will lead to serious deformation and oil leakage of the cylinder, as described in items 7 and 8. When installing cylinder head bolts, a torque wrench must be used and tightened in strict accordance with the torque and sequence required by the manufacturer.

20. Dust cooling system

Corrosion particles, scale, deposits or other products in the water jacket and radiator and the corrosion of water pipes will have a negative impact on the cooling efficiency of the cooling system. The resulting cylinder deformation will directly cause oil loss, such as items #7 and #8. Defects in the cooling system lead to overheating of the engine, and some cylinders may have local overheating areas, which will lead to scratches and adhesion of cylinders, pistons and piston rings, resulting in increased fuel consumption. Engine overheating and the overall oil temperature of the oil pan will also increase fuel consumption.

2 1. Dirty oil

If the oil is not changed according to the oil change cycle, improper maintenance of the oil filter will make the oil dirty, which will cause the oil to block the oil gap between the piston and the piston ring, resulting in an increase in oil consumption, as described in reason # 17. Dirty oil will also increase the wear of bearings, cylinders, pistons and piston rings. These worn parts, as explained in the corresponding article above, will lead to an increase in fuel consumption. Special attention: the consumption of dirty oil itself is higher than that of clean oil.

22. There is too much oil in the oil pan.

Due to the wrong insertion of the dipstick, the measured oil level is lower than the actual oil level, so new oil is added to make the oil level too high. If the bottom end of the connecting rod of the pressure lubricated engine touches the oil level, or the oil ring of the splash lubricated engine dips into the oil pool too deeply, the excess oil will be thrown to the cylinder wall and enter the combustion chamber.

23. Piston rings are not suitable for engine type or working type.

If a piston ring with an inappropriate size is selected (for example, a piston ring with an increase of 0.020 "is used in a cylinder with an increase of 0.040"), the oil in the upper part of the cylinder cannot be scraped back due to improper cooperation between the two, which will immediately cause oil leakage. Similarly, the gap between the bottom of the piston ring and the ring groove is also increased, which further increases the fuel consumption for the reason described in #26. Different types of engines and different working conditions require different specially designed and manufactured piston ring groups. Each type of piston ring group has a specific purpose. If it is used in the wrong place, it is impossible to control the oil consumption. It is very important to use the correct piston ring group.

24. High vacuum degree of engine

With the improvement of modern engine speed, valve overlap angle and compression characteristics, the vacuum degree of engine is improved. When some new engines slow down, the suction vacuum is as high as 25 inches (635 mm) Hg (old engine design = 508 mm Hg). High vacuum requires the development of a new oil ring to effectively seal both sides (up and down) of the piston ring groove to avoid oil leakage on both sides and back of the oil ring during high vacuum and deceleration. This reason is often the main reason for blue smoke or high fuel consumption. Therefore, it is very important to use an oil ring with side sealing ability when necessary.

25. The timing gear or chain is worn.

Wear of timing gear or chain will cause the timing of valve and crankshaft to be out of sync. Excessive backlash caused by gear teeth or chain wear makes the engine unable to adjust: the timing of the previous lap may be different from that of the next lap. When the movement of valve and piston is out of sync, it will cause excessive fuel consumption. The reason is that if the vacuum degree of the combustion chamber is too high, a large amount of engine oil will be pumped and burned.

26. When installing the piston ring, the circumferential end clearance is too small.

When installing a new piston ring, it must be noted that at the minimum diameter of the cylinder, the piston ring still has enough circumferential end clearance to compensate for thermal expansion. The clearance required for cast iron ring of general vehicle engine is 0.003-0.005 inch/inch aperture. Because the piston ring directly bears the combustion gas from the combustion chamber, the heating rate and working temperature of the piston ring are higher than those of the cylinder. Due to the water jacket, the temperature of the cylinder wall is low. This means that the piston ring expands more, so there must be a gap to compensate it-that is, the circumferential end gap-otherwise, when the engine is working, the end face of the piston ring will interfere and impact with the cylinder wall, which will lead to abrasion and adhesive wear, resulting in increased fuel consumption. If the engine keeps running, especially when the load is heavy, the adhesive wear will be more serious. The end face of the piston ring is pressed into the piston ring groove, and the gap between the ring and the cylinder wall increases. The high temperature and high pressure combustion gas in the combustion chamber directly burns the lubricating oil on the cylinder wall along this passage, and the gas escapes to the oil bottom, which greatly increases the fuel consumption. Serious interference may even lead to piston ring fracture, leading to the consequences as described in #27. Excessive circumferential end clearance of piston ring will also increase oil consumption.

27. Piston ring is worn or damaged.

If the piston ring is broken or excessively worn, so that the compression stress and gap cannot be maintained, excessive oil will be sucked into the combustion chamber during the intake stroke, and the combustion gas will flow down along the piston during the power stroke. Both of them will cause the combustion and carbonization of engine oil at the piston, cylinder wall and piston ring. The broken piston ring is more destructive, and the fragments with sharp mouth are likely to cut into the side of the piston ring groove, resulting in the damage of the ring row and the complete damage of the piston. When the engine is overhauled, the worn piston ring should be replaced immediately and not reused. The new piston ring has a quick positioning surface, which can control the fuel consumption immediately. The used piston ring, even if it is only slightly worn, cannot be positioned correctly because the surface is polished, which will also lead to excessive fuel consumption.

28. Piston ring sticking ring

Obviously, the piston ring of the rod ring can't control oil. So this situation should be avoided as much as possible. First of all, the installation of piston ring should ensure the correct piston ring side clearance, so that the piston ring can still move in the ring groove at the operating temperature when the engine is working. In addition, when installing the piston ring, make sure that all parts of the engine are clean and free of dust particles, otherwise, the piston ring may stick. Third, choose oil products with excellent performance to reduce the formation of carbon deposit, sludge and paint film. Fourth, you should change the oil and clean the oil filter regularly. Fifth, avoid engine overheating.

29. Valve timing lag

The valve timing lag makes the intake valve close for too long after the intake stroke starts, and the vacuum degree in the cylinder rises, which increases the probability that the engine oil is sucked into the upper combustion chamber of the cylinder from the gap between the piston, the piston ring and the cylinder liner and burned.

30. The oil pressure is too high

Incorrect oil pressure setting and failure of safety relief valve will lead to high oil pressure. As a result, the engine is saturated with excessive oil, which produces the same result as bearing wear. .

3 1. oil viscosity

The viscosity of used oil is too thin, which may cause high fuel consumption. Please refer to the vehicle maintenance manual to select the appropriate oil viscosity according to the driving conditions and ambient temperature.

32. Piston design

In order to meet the emission requirements of some latest engines, a new piston ring design is adopted. Sometimes, this design will have a slight "knock" at startup. Sometimes it will increase fuel consumption.

33. The internal gasket/air inlet is damaged.

In the new engine design, various composite materials made of metal and other materials are often used. Due to the difference of thermal expansion and cold contraction of different materials, after long-term operation, packing and seal will produce thermal stress fatigue or rupture, which will also lead to increased fuel consumption.

34. Early ignition and detonation

Most new engines are equipped with knock sensors to adjust the timing system to reduce emissions and improve engine power and performance. Pre-ignition knock is caused by pre-ignition of fuel during combustion. Pre-ignition leads to a sharp increase in the accumulated pressure on the piston, which destroys the normal movement of the piston ring, leads to the failure of the seals on the upper and lower sides of the piston ring, and finally leads to the leakage of the piston ring and the increase of fuel consumption. The same problem may also be caused by the failure of intake air flow sensor and throttle position sensor.

35. Modifications and spare parts used by users to improve engine performance.

Adding improved parts to the engine in stock or in use to improve the performance/power of the engine will increase the possibility of high fuel consumption.

36. Engine hauling

Heavy load refers to running the engine at a low speed when high speed (greater power/torque) should be used, which will cause the piston to bear more pressure and increase fuel consumption.

37. Incorrect overspeed operation

When the engine is not suitable for overspeed operation, there are many different reasons related to it, which will lead to the increase of engine fuel consumption. These situations include crawling and frequent parking in urban traffic. See also Reason 36.

38. The turbocharger seal leaks

The seal leakage of turbocharger will suck the oil into the combustion chamber, where it will burn and form carbon deposit, which will hinder the normal operation of the engine and further lead to more oil consumption.

39. AG air resistance

Excessive intake system resistance will increase the vacuum in the engine and increase fuel consumption, as mentioned in item 24. The serious blockage of the air filter is an example of this situation.

40.fuel dilution

If the completely burned fuel does not enter the lubrication system, the engine oil will become thinner and more volatile, resulting in higher fuel consumption. Due to fuel nozzle leakage, fuel pump failure, high intake resistance or excessive idling, excessive fuel may enter the lubrication system and mix with oil.